Vehicle brake signal



Aug. 7, 1943. T; VAN TUYL ETAL 2,326,808

VEHICLE BRAKE SIGNALS Filed Oct. 2, 1939 5 Sheets-Sheet l 1943. T. VAN TUYL ET AL 2,326,808

VEHICLE BRAKE SIGNALS Filed Oct. 2, 1959 5 Sheets-Sheet 2 1943. T. VAN TUYL ET AL VEHICLE BRAKE SIGNALS Filed Oct. 2, 1939 5. Sheets-Sheet 5 Aug. 17, 1943. T. VAN TUYL ETAL VEHICLE BRAKE SIGNALS Filed 001:. 2, 1939 5 Sheets-Sheet 4 Aug. 17, 1943.

T. VAN TUYL ET AL 2,326,808

VEHICLE BRAKE S IGNALS Filed Oct. 2, 1939 5 Sheets-Sheet 5 7 41444 m Mfl Patented Aug. 17, 1943 VEHICLE BRAKE SIGNAL Thomas Van Tuyl and Charles B. Hale, Chicago, 111.

Application October 2, 1939, Serial No. 297,534

3 Claims.

The object of thepresent invention is to produce a simple, novel and reliable means for apprizing others near by of the fact when the brakes of an automobile or other vehicle are being suddenly applied. r

In carrying out my invention, a signalling de vice, which is preferably an alarm, is controlled by some movable part of the brake apparatus which receives a sharp impact when an emergency application of the brakes is made; and the invention may therefore, in one of its aspects, be said to have for its object to produce a simple and novel controlling device for a brake signal which operates when such moving part receives a sharp blow o 1 is subjected to a sudden impact, but remains inoperative during movements of such part'in normal or ordinary brake application.

it is desirable, also, to warn the driver of a vehicle when the brakes become defective, A further object of the present invention is to combine with the aforesaid. signal means to warn the driver that the brakes need attention.

The various features of novelty whereby the present invention is characterized will hereinafter be pointed out with particularity in the claims; but, for a full understanding of the invention and of its objects and advantages, ref erence may be had to the following detailed doso *iption taken in connection with the accompanying drawings, wherein:

Figure l is a side View of an automobile brake pedal and a fragment of the steering post, having mounted thereon one form of the new signalcontroliing devices, and there being a fragment of the vehicle floor shown in section; Fig. 1A is a diagram illustrating the signal and alarm circuit; Fig. 2 is a top plan view of the parts shown in Fig.1, the floor being shown in section; Fig. 8 is a front view of the controller shown in Figs. 1 and 2, but on a much larger scale; Fig. 4 is a vertical section, on a plane extending from front to rear, through the controller and its supporting clamp or bracket, on the same scale as Fig. 3 and showing theparts, including a fragment of the brake pedal, in the same positions as in Fig. 1; Fig. 5 is a side view of the controller, a portion of the casing being broken away to expose the interior, and the parts of the controller in the positions which they occupy when alarm is being sounded by reason of an emergency application of the brakes; Fig. 6 is a viewsimilar to Fig. 5, showing the parts of the controller in the positions which they occupy when, because of defective brakes,

it is necessary to press the pedal far down; Fig. 7 is a section on line '|'l of Fig. l, the wire actuator being shown in elevation; Fig. 8 is a view of the controller casing or housing taken on line l-'|' of Fig. 4, but looking in the opposite direction from that in which the arrows are pointing; Fig. 9 is a section on a larger scale, taken approximately on line of Fig. 4, showing the device for clamping the controller to the brake pedal as it appears before the clamping screw has been tightened, the screw being indicated in dotted lines in an intermediate position; Fig. 1%) is a view similar to Fig. 9 showing the clamp tig .;ned upon the pedal; Fig. 11 is a side View a fragment of the steering post and one of the stop devices for the signal apparatus, together with the means for supporting the stop device on the steering post; Fig. 12 is a section taken approximately on line 52-12 of Fig, 11, the stop device and the acent part of its supporting bracket being shown in elevation; Fig. 13 is an elevational View of the bracket appearing in Figs. 11 and 12; 14 is a section through the dash of an automobile, showing in elevation a signal lamp and a device for clamping it to the dash; 15 is a top plan view of the parts shown in Fig. 14, with the exception of the dash; Fig. 16 is a View oi the master cylinder and liquid reservoir of a hydraulic brake system, partly in elevation and partly in section, illustrating the manner in which the signal controlling means may be incorporated in that structure; Fig. 17 is a section taken on line il-ll of Fig. 16, only the upper half of the cylinder being shown; Fig. 18 a section on line 18-48 of Fig. 16, showing only the sam upper half of the structure that appears in 17; Fig. 19 is a central vertical longitudinal section through another type or head, and a fragment of the master cylinder, in a construction wherein the controlling devices are associated with the master cylinder; Fig. is a section on line 20,2.i of Fig. 1?); and Figs. 21 and 22 are sections taken respectively on line 22i-2i of Fig. 19 and line 22-22 of Fig. 20, looking in the direction of the arrows.

Referring to Figs. 1 to 8 oi the drawings, i represents the usual or any suitable brake pedal of an automobile and '2 the usual or any suitable steering post positioned near the brake pedal; both extending through the more or less upright portion 3 of the floor or" an automobile. Carried by a suitable bracket clamped upon the pedal in front of or underneath the floor, in a manner to be hereinafter described, is a forwardly relatively to the casing. Upon being pushed past dead center the resetting of the trigger is completed through the action of the spring 25, the trigger again assuming the position which it occupies in Figs. 4 and 6.

The stop for resetting the trigger may take any usual or suitable form. In the arrangement shown, there is a U-shaped member 38 composed of a heavy wire or a light rod, adjustably secured to the steering post and having an extension of one leg bent laterally as indicated at 39, (best seen in Fig. 2), behind and in the path of movement of the upper end of the trigger-setting lever. Therefore, whenever the brake pedal returns to its normal idle position, the free end of the lever 26 strikes the part 39 on the stationary stop device and causes a resetting of the'trigger if it happens to be in its switch-closing position.

It is desirable that the sensitiveness of the trigger be adjustabl to the needs of each particular brake apparatus and, also, that it be possible to adjust the setting from time to time, as conditions demand. To accomplish these aims, means are provided to limit the distance that the trigger travels past center in the setting thereof;

the closer the trigger is to being at dead center, the more sensitive it will be and the smaller the blow or impact needed to make it operate. The stop illustrated consists of a nut in the form of a wedge-shaped block 40 resting against the front wall of the casing and held in position by a long screw 4| that extends throughout the entire length of the casing and has as its upper end a slotted head 42 by means of which it may be turned. The screw is held against movement, except a rotary movement about its axis. Lateral movements in any direction are prevented by the bearing surfaces whichsurround the two ends of the screw. Lengthwise movements of the screw may be prevented by providing the screw with an annular groove 44 just underneath the head, and utilizing the plate 24 as-a key portions of which enter this groove. It will be seen that the inclined face of the block 40 and the lower half of the trigger are parallel to each other at the time that the trigger engages the block. Therefore, it the screw be turned in one direction, it will permit the spring 25 to shift the upper part of the trigger farther to the right as viewed in Fig. 4 whereas, if the screw is turned in the other direction, the block is shifted in a direction that causes the trigger to be carried closer to dead center.

It will thus be seen that the sole purpose of the trigger is to sound an alarm when an emergency application of the brakes is made, for it has no effect on the switch finger 14. In order to cause th switch l4 to close the lamp circuit, there is provided on the steering post a second stop device 45 similar to the one previously described; this stop device being placed well forward so that its stop element 46 is not engaged by the lever 26 unless the foot pedal is pressed so far down that there must be something wrong with the brakes. Whenever the foot pedal moves down far enough, the lever strikes the stationary stop element 46 as shown in Fig. 6, causing the leg 33 of the lever and its lateral projection 34 to press the contact finger I4 rearwardly and engage it with the finger I3, thus closing the circuit of the warning lamp. Also, by properly proportioning the parts, both of the fingers l3 and 14 may be driven back until the finger I3 engages with the finger l2 and causes the horn to blow, in addition to energizing. the" lamp. It will be seen that window 58.

thecalibration of the device maybe such that the horn will not be sounded whenever the brakes are applied, even though the brakes need servicing; only the lamp circuit being closed when the condition of the brakes is not very bad, and thus warning the driver that if he does not get his brakes fixed the horn will begin to sound when ever he presses down on the brake pedal.

In Figs. 9 and 10 there is illustrated a novel means for clamping the bracket 4 to the pedal. It will be seen that the bracket contains a hole extending through the same from front to rear and having opposed fiat, parallel sides 41. The other side of the hole may be of any desired shapes although they are also shown as being flat and as having wide, low central ridges 48 extending throughout the length thereof. Each of the flat walls 41 merges at its ends into curved sections 49 that give a flaring eflect to the two ends of the hole. Extending through the hole in the bracket is a metal strap 50 which is first looped about the pedal, from the rear, and the ends of which are then inserted in the hole in the bracket; each end portion lying flat against one of the flat faces 41. After this assembly has been made, the strap may be drawn taut and the parts that project forwardly from the bracket may be bent laterally as indicated in Fig. 9. A thread cutting screw 52, of the proper size, namely, of a diameter about equal to the distance between the ridges 48 and somewhat less than the distance between the strap sections located in the hole, is then partially entered from the front between the strap ends. Upon turning the screw, it cuts a thread in each strap end and gradually draws the strap tightly about the pedal, by reason of the fact that the two strap ends are drawn forwardly by the screw as'long as there i any slack to be taken up. In order to prevent the head of the screw from clampin the strap ends between it and the front face of the bracket, grooves 53 are cut across the front face of the bracket in registration with and for a height equal to the vertical dimension of the flat sides 4'! of the hole in the bracket; the depth of these grooves being at least as great as the thickness of the strap material. Consequently, the head of the screw does not press against the protruding strap but simply serves as a guide that permits the strap ends to creep laterally and rearwardly until the condition. illustrated in Fig. 10 results.

In Figs. 11 to 13 there is illustrated a simple device for supporting either of the stationary stops 38 and 45. This device comprises a bracket in the form of a stifi plate 54 having therein two sharp bends in the same direction. The parts are so proportioned that when the bracket is set against the steering post with the latter resting in the angle between one end section 55 and the central section of the bracket, the other end section may be brought into a plane parallel with the plane of movement of the pedal. The end section 55 has in the free end a wide notch 56, while the central section, 51, contains a wide A strap 59 is threaded through this window and carried along the outer face of the bracket to and through the notch 56; the two ends of the strap being carried around the steering post from opposite sides, and being joined together by a bolt 60. In this way the bracket is tied tightly to the steering post. As shown, the strap has bolt-receiving holes 6! distributed along the same. The bracket may be provided at the corner between the sections 55 and 51 with an outwardly projecting boss 62 adapted to enter one of the bolt holesrin thestrap to prevent slippage between; the strap and the bracket; The corresponding;stationary stop isseoure'dto the bracket :by means of a1short; ,he'aded strew extending between thelegs of the U-shaped portio'n thereof andinto; the bracket. Between the un-shaped partandgthe bracket on the onefside er n d e w e nos are bent upwardly into ,;S 'h 1;iiO d 100lQ }i whosezeomrnon axis parallel with the p of the cross me nber 'of thebraoketi51 In other words, when-thejlampis placed underneath the dash so that the cross member of, the bracket is lane a spring 38 which bears at its front end against thevalve and at its rear end against a flange or roller. 89 on the rear end of the stem; This spring normally holdsthe primary pressure valve seated against the return valve closing that part of the cehtraljhlaeriihgintlie latter that surrounds. the stem 88-. The'valve ttjhas deep hotches fifl hutintopthe same through'the .front edge of its cylindrical wall and is of reduced external, diameter in'the notched region; thereby provio ng an. annular space between the front hollow rivetiitwhich preferably passes through. 7 a toothed washer.

horizontal; the loops Til arei'vertical andtheir free.

endsjli'e at considerable distances iron). the brachet. While not truly so,ithe loops may roughly be described as beinghelical. Atany rate, the

- loopsliemainly above the plane of the flat portion of the V; with the-extreme ends, when ireeto do so, eirtending somewhat below plane as shown in dotted lines in Fig. 14. Therefore, lwhenthe lamp lfSJSHd ll lrlerneath the horizonte'l flange of the dashfrom ,the right as viewed in Fig. 14, the free ends oifthe wires must be'liited so as tocarry them on topofjthe flange; where they will exert a downward 'pressure which acv.co lpa-nied by. the biting action Of: the washer "EG,-serves.to hold p a ement. 1

the present invention incorporated. inthe master cy i e uni o .ajhycraul c b en vst m e.- i'erring' to these fi'gur s fifirepresents any us a1 or suitable master cylin er; 1%: the 'piston th n, and "i a reservoir gfor jorake; fluid; the pist shown. The cylinder has at 'one'end a; ;head '38 held in place by a sleeve-like-nutflii. lE rran-ged within the cyiinderis alareedisk valve 38 which n ma y es a st a annular l orfiame Bl .Olfl llll; inner end of the head and f tting into the. cylinder. The valve 8 3 has -:p e ri-pheral notches 82 through which fluid may-pass when the valve is unseated. A long, light compression spring Siextends between'the piston and the "valve to hold the latter yieldingly against its seat, while'permitting it to be unseated wnen brake fluid is required t-o'return from the system into the cylinder.

.Thehead it is in at Term of a thiek-walled cylindrical sleeve and slidablein the same,;is a

cup-shaped primary pressure. valve 535 whose I 1 closed end normally bear against the rorward face of'the return valve 8% 'The valve 85 *has'a rearwardly extending tubularstem open 'at its rear end' andopening at its front end. into the theilarnp -securely against disbrined t to. he. o e ..t w l he; h tin Fig. 16, by. the 'Operati of the usual pedahn ot end of the valve and the surrounding Wall-of the cylinder head; y

- Slidab'ly'fittedin the body of the valve 85' is a secondary. pressure valve. 9! in the form of a cylindrical-block having wide, shallow peripheral grooves 52 "distributed about the same and extending; throughout thelength thereof. ,w The valve in has a tubular'cstem 9-,,srriall'er.in external diameter, than :the internal diameter of the stern '35; extending through; and projecting heyond the rear end ef the latter. member 91 has an axialbere, therear section of which is somewhat smaller in diameter than the interior or the stem 9 whilethe front section is still smaller in diameter; Arranged-in the front seei- .tion of the bore in member 5i is a plunger 95 provided with a head situated the forward end of the rear sectiono f the bore and serving as a stop to. limit the forward movement of l the plunger. Behind the plunger-is a iight compressiongsprin-g 95 that normally holds "the header th'eypluh er seat-ed against the shoulder formed at the junctur of the two sections of the bore in against which therea-r end offt'hespringfifi bears whichzserves as an abutment for astrong pompressionspring 98 disposedwithin the stem;

tending through a cap; iQ-l screwed 'upon "the 7 rear end of the stem. The valve 9: is normally heldseateol against the facethat fo-rrnsthe hottern of the'cupi-n valve 65, by a-spri'ng +93 which gagement with the fruit F31; The washer is slidablegon thelrsteni but inter-locked with the "same and w hthenut, by :a'keyfinthe shape of aftongireyi projecting rearwardly from the washer; thelatterthus acting 'a's'ainut lock; h 1

It will be seen that the presence or" the-flange ti on the rear end ofv the cylinder head iii-creates arshallow chamber 1% lying between'the rear end of the -head proper and the return valve sfi, intojwhioh passage fluidrmay r-flow from the jinaster cylinder when the valve 35 is pushed forward; awayirom the return. valve. For the fluid their to reach the outlet tit? connected to "the "chamber i 52 in the head in 'frontof the valve 85, aflon'gitudihal:passage i823 is provided 'in the eynimrrai wall"'"'tl'i'e' head; A- por t me ers from this; I v

in f ront the"valve Theiorward end chamber within theyalve. --'Ihis stem extends throughan opening "'31, or greater "diameter (than V thestemin'thecenter of the return valve. nourrounding the stem', behind the return valve, is

sta e iiit'o the cha'iiibeiwithin the ward sectionofthe passage is sci ewed. a suit e tri e oft ravin -castrate end erteiiciise n b the sruallerjrear section, easel-Being thief-valve in or-out the effective size-o1" the passage through.

whichfluid iriust fiowtoreach'themortfl illunay be decreased*o'r'irlcreased; therebyrhaking it pose sible to regulate the rate of flow for a given pressure on the fluid.

Normally the parts are in the position illustrated in Fig. 16. 7 When the brake pedal is pressed in making an application of the brakes, the piston I8 moves forward, namely, to the left, forcing the fluid in the cylinder against the valve 85. The pressure of the fluid unseats this valve and permits fluid to flow through the central opening 81 in return valve 80, into chamber I06, and through port I09 and to outlet I01. The Valve 85 need not open far to permit fluid to enter the passage I08 as fast as it can flow past the regulating valve IIO. However, if an emergency application of the brakes is being made, the brake pedal being moved by impact rather than by a steady pressure, the fluid cannot escape through the passage I08 fast enough and the valve 85 is forced to the extreme forward limit of its movement, closing the port I09. The pressure of the liquid against valve 9| now forces that valve open, so that the braking fluid reaches the outlet by flowing through the interior of the valve 85, and out through the notches 90 in thelatter.

In the event that there is a fault in the brake system that makes it necessary to push the pedal far down in order to obtain a braking effect, the piston I6 will strike the rear end of the plunger 99 and will push the valve 9| forward.

Whenthe brake pedal is released after a braking stroke has been made, the brake fluid again flows back toward the master cylinder, forcing the valves 85 and BI back until the return 'valve 80 is unseated. Thereupon brake fluid flows through the port I09, passage I08, chamber I08 and notches 82 in the periphery of the valve 80, into the master cylinder I5.

The abnormal valve movements just described are utilized to give the signals heretofore described. For this purpose the valve 85 and the plunger 95 serve as movable contact pieces adapted to cooperate with stationary contacts in a plug II 2 of insulating material closing the front or outer end of the sleeve-like cylinder head. Embedded in' and coaxial with this plug is a metal sleeve II 3 having its rear end exposed in the chamber I02; the diameter of the said end of the sleeve being equal to the diameter of the valve 85. Consequently, when the valve 85 is driven forward far enough to close the port I09. it contacts the sleeve II3 to which the conductor I forming part of the horn circuit is connected. Fixed in and extending coaxially through the plu H2 is a rod I I4 of conducting material, the rear end of which is contacted by the plunger 95 when the brake pedal is pressed down at a time when the condition of the brake systemis such that a normal movement of the pedal does not suffice to apply the brakes. The conductor I'I, forming part of the warning lamp circuit, is connected to the outer end of the rod I I4.

The movable contacts are of course grounded through the master brake cylinder unit, just as the contact finger I3 in the other form of the invention is grounded. In order to insure a good electrically conductive path from the valve 85, forming one of the movable contacts, there is placed within a radial socket in the cylindrical wall of the cylinder head a cup-shaped contact shoe I I 5 behind which is a spring I I6 that presses the shoe at all times against the outer surface of the valve.

In the arrangement shown in Figs. 19 to 22, the

16 to 18, inclusive, although being the same in principle. The cylinder head I20 in Figs. 19 to 22 is similar to the head 18, but is somewhat longer, and being more in the nature of a solid cylindrical block having large cylindrical bores extending longitudinally thereof and opening out through the front end. As there are three valve devices employed in this construction, there are three of. the longitudinal bores indicated at I 2I I22 and I23, respectively. The rear end of each of these bores terminates at the inner end at a flat transverse surface on an end wall I24, but communicates with the interior of the cylinder I5 through a port or a passage coaxial therewith, extending through said wall I24, as indicated at I25, I26 and IZ'I, respectively. Screwed into the bore I2I, from the outer end of the head, is a. long thick-Walled sleeve I28 provided near the rear or inner end with a peripheral groove I29 communicating with the interior of the sleeve through a series of ports I30. The bore in the sleeve is reduced in diameter at the rear end of the sleeve, beyond the ports I 30, as indicated at I32. Screwed into the sleeve, so as to be accessible fromthe outside, is a needle valve I33 cooperating with the port or passage I32. In the bore I 2|, between the wall I24 and the rear end of the sleeve I28, is a sliding cylindrical block I34 which, when pressed rearwardly, serves as a valve to close the port or passage I25. The block is reduced in diameter at the extreme rear end and, in this part of reduced diameter, are a series of radial ports I35 communicating with an axial bore. I36 extending into the block from the front end but stopping short of the rear end of the block. Arranged in the bore I36 is a compression spring I31 abutting at its forward end against the rear end of the sleeve I28 and thus normally serving to hold the block in position to close the port I25. The annular chamber comprising the groove I29 communicates with the bore I22 by means of a passage I38 in a region where the bore I22 is intercepted by a bore I39 extending up through the bottom of the head for the reception of the nipple portion of the outlet device I 01.

Therefore, as long as the inlet from the passage I38 to the bore I22 is not closed, pressure on the pedal to apply the brakes will cause brake fluid to flow through the passage or port I25, pushing the block I34 toward the left, as viewed in Fig. 19; and the fluid will then flow through the radial ports I35, passage I35, port or passage I32 and ports I30 into the groove I28 and from there through the passage I38 to the distribution system through the outlet I01. The rate at which the braking fluid flows under a given pressure may be regulated by means of the needle valve I33; this valve being set so that the flow shall be sufliciently rapid to take care of ordinary brake applications.

Associated with the bore I22 are devices which cause the horn to sound when an emergency application of the brakes is being made. Screwed into the outer end of the bore I22 is a plug I4I through which extends and into which is fixed a long rod-like contact member I42 the outer end of which is connected to the wire I5 forming part of the horn circuit. The rod I42 is insulated from the plug by means of a surrounding sleeve I43 of insulating material, and there is a Washer I44 of insulating material placed between the nut I45 and the end of the plug. The inner end of the rod extends into the interior of the bore I22 so as to bring its rear end just below the passage! 3,8, andit is surrounded by a block 545 ,cf, insulating [material that fits into the" bore iii and abuts. against the rear tend of the plug. In the rear endcf the pore l2?! i a long cup-sha edpart l el 'hav ing its closed end.

through which it" extends and in which it is. a

slidable fit; 1 A hole l 52 i bored centrallyrthrough the plug le end far enough intothe. stem eXtencl behind the rear face of th cylinderhead. when the plug is seated against'the frcntiiace' pf-the wall J24. Radial holes E53 lead to the exterior of the stem from the centralhole or bore at a point which is just behind the cylinder head when the plug l d is inv its rearmost. position, as shown in Fig. 20.. :Within. the chamber in aaaeeos than the diameter of the bore; the four corners 'cf'the block havingbeen machined so as to form narrow sections of a cylinder of the same diameter as the bore 822. The block 59 is provided with a rearward extension ltll in the form of a stem-like element longer than the stem 55!).

, The block IE9 is hollow,'and there is a core or the part lll'l is-a forwardly seating check valve iSAljcooperating, with the port iii-.8; this valve being normally held closed by means of a light Compression spring H55 engaged with the rear face 'thereofland. extending into and bottoming in the hole or bore 552. V In thehorelZZ; in front of the part saris a compressicnspring B56 engaged at one'end with the block l l'fijofinsulating .materialancl at its other end with. the front face of the part l l'l.

Normally the spring lfifi holds the par-1; il il in the position shown inFig. 20, and the sprin I55 holds the check valve closed; In the opera- 7 tion oi the brakes the checkvalve permits the the brake fluid cannot move fast enough through I the passage controlled by the needle valve,-the pressure that i built up in the master cylinder forces the unit oi-which the part ll and'the stem I59 are elements toward the'left, as shown in Fig. 20, causing the check valve 54 to, strike. against the rear end of the contact rod M2 and thus closing the circuit through thehorn. This resultsin the shutting ofi of the passage i353 through-which the brake fluid travels in ordinary operations of the brakes and makes it necessary to provide additional means for permittingv the brake fluid to reach thedistrlbution system. Such additional means are contained in the bore I23. 7

Into the front end of the'bore lZ-E-is screwed a plug l5! similar to the plug l4! and containing a rod lE-Zi similar to the rod but projecting less far beyond the rear end of the plug than does the rod-M12. In the rear end of the bore l2-3 is a long block Hi3 having a fiat rear face to serve as a valve to close the port I2! and having an external contour such that it is slidahly held. in the bore and-yet provides ample hetween'the outer surfaces thereof and the sur: unding cylindrical wall to permit a'free flowof brake fluid when occasion demands. In the arrangement shown, this block is approximately square incross section, meaning thereby that its'cross sectional shape was that ofa square whose diagonals were somewhat longer passage l5l extending from the chamber within the block rearwardly into the stem.

which protrudes from the block and has itsfront end spaced a short distance from the rear end of the'contact rod ltd when, the block N59 is in its rear-most position, as shown in Fig. 20. Behind the-part 962 is aspring I63 which normally holds it in its "forward position. Q Extending through this spring is a long stein l i l'projecte ing rearwardly from'the' part Hi2 and adapted to enter the bore it! when the part 562 is pushed back into the block. Between a blockioi insulating material E65, surrounding the rearwardlyprojecting end of the rod 95.8 and similar to, the block Hi3 and theirontend of the block. item a strong compression spring IE6 that normally holds the block in position to close the port 521. Inv an emergency operation of the brakes,

when other passages between the master cylinder and. the distributing'systemare closed, the pressure in the master cylinder forces the member I59 toward'the left, as viewedrin Fig. 20, permitting brake fluid to flow through the port l2! past the member l59and downinto. the chamber [3%. The port l2? is considerably larger than'the, cross sectional area of thestem its, .a'nd there is ample room for the fluid to travel past-themember" lES, so that themem ber i591 need not move far enough to cause the ttl p u or plun er 52 to enga e the contact rod let, Consequently, the lamp circuit, the wire l! of. whichis connected to. the. rod 158, does not close during ordinary or emergency operations. ofithe brake. l-lowevenii the bra system contains v a, leak, or one of the pipes should. be broken, or i'fcvfor, any other, reason,

" an excessive movement. of the piston in the ma s ter'. cylinder takes place upon depressing the pedal, the, piston will strike the stem 168 and will force, the member I59. far enough forward. or to the left, as viewed in Fig. 20, to. close the lamp circuit It will also be seen that if the brake system is in a very load, condition, the pisward until the horn circuit is closecl a-nd the horn is caused to sound. I

In the, construction just described, as in the case. of that disclosed inFigs. 16 to 18,,the movable contacts E55 and E62 are grounded, so that each, movable contact 'need'only be engaged with its cooperating stationary contact to close the corresponding circuit.

We claim: 1. In combination, two signals, acasing adapted to be fixed upon a brake pedal, two two-position controlling devices, one for each signal, arranged in the casing, an inertia-operated actuator mounted in the casing to move from, an idle position and drive one of said con trolling devices into its working position when the pedal is driven down quickly, a member mounted, on the casing and yieldingly held in an idle position, said member being movable-in one direction from its idle position to move both controlling devices into their, working positions and movable in the'opposite' direction from said Slidably within the blocl: 559 is acylindrical plug H52 idle position to reset the actuator, said member having a part lying on the exterior of the casing and adapted to engage an upper stationary stop to reset the actuator when the pedal rises and to engage a lower stationary stop to move it in the direction to shift both controlling devices into their working positions when the pedal moves down abnormally far as is the case when brakes are defective.

2. In combination, a casing adapted to be fixed upon a brake pedal, a two-gap switch within the casing, an inertia-operated actuator mounted in the casing to move from an idle position into engagement with a part of such switch and close one of said gaps when the edal is driven down quickly, a member mounted on said casing and yieldingly held in an idle position, said member being movable in one direction from said idle position to engage a part of said switch and close both of said gaps and movable in the opposite direction from said idle position to reset said actuator, said member having a part lying on the exterior of said casing and adapted to engage an upper stationary stop to reset the actuator and to engage a lower stationary stop to close both gaps in said switch when the pedal moves down abnormally far due to defective brakes.

3. In combination, a casing adapted to be fixed upon a brake pedal, two signals, two switches, each controlling one of said signals, arranged within the casing, an inertia-operated actuator mounted in the casing to move from an idle position into engagement with the movable part of one of such switches to close the same when the pedal is driven down quickly, a member mounted on said casing and yieldingly held in an idle position, said member being movable in one direction from said idle position to engage the movable part of the other 01 said switches and close both of the switches and movable in the opposite direction from said idle position to reset said actuator, said member having a part lying on the exterior of said casing and adapted to engage an upper stationary stop to reset the actuator and to engage a lower stationary stop to close both switches when the pedal moves down abnormally far due to defective brakes.

THOMAS VAN TUYL. CHARLES B. HALE. 

